This invention relates to the art of automatic fastening means, and more particularly to a new and improved control system and method for such machines.
One area of use of the present invention is in slug riveting methods and apparatus, although the principles of the present invention can be variously applied. The various fastener installation operations performed by automatic fastening machines have been controlled by CNC (computer numerical control) or PLC (programmed logic control) systems. The ability for a CNC or PLC controlled automatic slug riveting machine to produce a satisfactorily formed fastener is controlled through many variables. One of the most underlying problems is the rate at which these controls can respond to their respective process feedback devices.
It would, therefore, be highly desirable to provide a new and improved control system for automatic fastening machines which provides a significant reduction in the overall cycle time for installation of a fastener, which has a relatively rapid system response, which reduces communication time lags between system components, which eliminates the need for mechanical hard stops and electrical position switch indicators thereby reducing the probability of machine breakdowns and which simplifies the set up times associated with matching tooling cavities with motion involved in the fastener forming process.
The present invention provides a control system and method for automatic fastening machines wherein a multi-axes motion controller is utilized in place of the conventional PLC or CNC control to provide for virtually an immediate change in system response when the systems feedback devices indicate the need for variance. The major advantage of the process control approach of the present invention is that all system feedback information is controlled via a single on board processor thus eliminating any communication lag associated with multi controller applications. This also provides for an improvement in fastener installation cycle time. An additional advantage to the approach of the present invention is the elimination of many mechanical hard stops and their respective electrical position switch indicators, which in turn reduces the chance for machine breakdowns resulting in a greater increase in productivity. The new control architecture of the present invention is utilized to control an xe2x80x9canti-winkxe2x80x9d automatic slug riveting process which improves fastening accuracy, reliability and cycle time. This technique of fastening provides for virtually no work piece movement during the forming process allowing for the use of rigid fixturing.
The foregoing and additional advantages and characterizing features of the present invention will become clearly apparent upon a reading of the ensuing detailed description together with the included drawing wherein: